scholarly journals Sensitivity Analysis for the Decomposition of Mixed Partitioned Multivariate Models into Two Seemingly Unrelated Submodels

2014 ◽  
Vol 43 (3) ◽  
pp. 167-179
Author(s):  
Eva Fišerová ◽  
Lubomír Kubáček
Keyword(s):  
Sensitivity Analysis ◽  
Covariance Matrix ◽  
Parameter Space ◽  
Variance Components ◽  
Multivariate Model ◽  
Test Statistics ◽  
Multivariate Models ◽  
Test Statistic ◽  
Significance Level ◽  
Safe Region

The paper is focused on the decomposition of mixed partitioned multivariate models into two seemingly unrelated submodels in order to obtain more efficient estimators. The multiresponses are independently normally distributed with the same covariance matrix. The partitioned multivariate model is considered either with, or without an intercept. The elimination transformation of the intercept that preserves the BLUEs of parameter matri- ces and the MINQUE of the variance components in multivariate models with and without an intercept is stated. Procedures on testing the decomposition of the partitioned model are presented. The properties of plug-in test statistics as functions of variance compo- nents are investigated by sensitivity analysis and insensitivity regions for the significance level are proposed. The insensitivity region is a safe region in the parameter space of the variance components where the approximation of the variance components can be used without any essential deterioration of the significance level of the plug-in test statistic. The behavior of plug-in test statistics and insensitivity regions is studied by simulations. 

scholarly journals Examination of Lifelong Learning Trends of Physical Education and Sports Teachers on Different Variables

2020 ◽  
Vol 9 (6) ◽  
pp. 94
Author(s):  
Alpay BÜLBÜL
Keyword(s):  
Physical Education ◽  
Lifelong Learning ◽  
Research Data ◽  
Physical Education Teachers ◽  
Test Statistics ◽  
Test Statistic ◽  
Significance Level ◽  
Normality Test ◽  
Learning Competence ◽  
Academic Year

Objective: The aim of this study is to examine the lifelong learning trends of physical education and sports teachers with regard to various variables and to compare them with the literature. Method: 113 physical education teachers working in secondary schools and high schools in Tokat province and its districts during the 2019-2020 academic year participated in the study. In order to obtain the research data, the “Lifelong Learning Scale” adapted to Turkish by Engin, Kör and Erbay (2016) and the demographic information questionnaire created by the researchers were used. This research is a descriptive study in scanning model. The research data were subjected to normality test and the research data were analyzed according to the results. In the analysis of the data, 0.05 significance level was taken as the criterion. In order to determine the level of lifelong learning competence of physical education and sports teachers, the variables with 2 level were analyzed by using t test statistics, and the variables with 3 or more levels were analyzed by the ANOVA F test statistic. Conclusion: According to the results of this study which was conducted on different variables, physical education teachers’ lifelong learning tendency scores are high. At the same time; gender, professional seniority and and the lvel of the institution (primary school, high school etc.) are not effective factors on lifelong learning motivations og physical education and sports teachers.

scholarly journals Probabilistic sensitivity analysis for multivariate model outputs with applications to Li-ion batteries

2018 ◽  
Vol 1039 ◽  
pp. 012020 ◽  
Author(s):  
V. Triantafyllidiis ◽  
W.W. Xing ◽  
P.K. Leung ◽  
A. Rodchanarowan ◽  
A.A. Shah
Keyword(s):  
Sensitivity Analysis ◽  
Probabilistic Sensitivity Analysis ◽  
Multivariate Model ◽  
Li Ion Batteries ◽  
Li Ion

scholarly journals Effects of kinship correction on inflation of genetic interaction statistics in commonly used mouse populations

2021 ◽  
Author(s):  
Anna L Tyler ◽  
Baha El Kassaby ◽  
Georgi Kolishovski ◽  
Jake Emerson ◽  
Ann E Wells ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Genetic Interaction ◽  
Recombinant Inbred Lines ◽  
Test Statistics ◽  
Test Statistic ◽  
Kinship Matrix ◽  
Main Effect ◽  
Main Effects ◽  
Interaction Test

Abstract It is well understood that variation in relatedness among individuals, or kinship, can lead to false genetic associations. Multiple methods have been developed to adjust for kinship while maintaining power to detect true associations. However, relatively unstudied, are the effects of kinship on genetic interaction test statistics. Here we performed a survey of kinship effects on studies of six commonly used mouse populations. We measured inflation of main effect test statistics, genetic interaction test statistics, and interaction test statistics reparametrized by the Combined Analysis of Pleiotropy and Epistasis (CAPE). We also performed linear mixed model (LMM) kinship corrections using two types of kinship matrix: an overall kinship matrix calculated from the full set of genotyped markers, and a reduced kinship matrix, which left out markers on the chromosome(s) being tested. We found that test statistic inflation varied across populations and was driven largely by linkage disequilibrium. In contrast, there was no observable inflation in the genetic interaction test statistics. CAPE statistics were inflated at a level in between that of the main effects and the interaction effects. The overall kinship matrix overcorrected the inflation of main effect statistics relative to the reduced kinship matrix. The two types of kinship matrices had similar effects on the interaction statistics and CAPE statistics, although the overall kinship matrix trended toward a more severe correction. In conclusion, we recommend using a LMM kinship correction for both main effects and genetic interactions and further recommend that the kinship matrix be calculated from a reduced set of markers in which the chromosomes being tested are omitted from the calculation. This is particularly important in populations with substantial population structure, such as recombinant inbred lines in which genomic replicates are used.

A boundary crossing probability for the Bessel process

1998 ◽  
Vol 30 (3) ◽  
pp. 807-830 ◽  
Author(s):  
Rebecca A. Betensky
Keyword(s):  
Nonparametric Test ◽  
Bessel Process ◽  
Boundary Crossing ◽  
Test Statistic ◽  
Boundary Crossing Probability ◽  
Significance Level ◽  
Straight Line ◽  
Crossing Probability ◽  
Nonparametric Test Statistic ◽  
First Crossing Time

Analytic approximations are derived for the distribution of the first crossing time of a straight-line boundary by a d-dimensional Bessel process and its discrete time analogue. The main ingredient for the approximations is the conditional probability that the process crossed the boundary before time m, given its location beneath the boundary at time m. The boundary crossing probability is of interest as the significance level and power of a sequential test comparing d+1 treatments using an O'Brien-Fleming (1979) stopping boundary (see Betensky 1996). Also, it is shown by DeLong (1980) to be the limiting distribution of a nonparametric test statistic for multiple regression. The approximations are compared with exact values from the literature and with values from a Monte Carlo simulation.

A test for fuzzy exponentiality based on Kullback-Leibler information

2021 ◽  
pp. 1-8
Author(s):  
Lingtao Kong
Keyword(s):  
Biological Sciences ◽  
Monte Carlo ◽  
Goodness Of Fit ◽  
Experimental Studies ◽  
Real Data ◽  
Test Statistics ◽  
Test Statistic ◽  
Goodness Of Fit Test ◽  
Higher Power ◽  
Leibler Information

The exponential distribution has been widely used in engineering, social and biological sciences. In this paper, we propose a new goodness-of-fit test for fuzzy exponentiality using α-pessimistic value. The test statistics is established based on Kullback-Leibler information. By using Monte Carlo method, we obtain the empirical critical points of the test statistic at four different significant levels. To evaluate the performance of the proposed test, we compare it with four commonly used tests through some simulations. Experimental studies show that the proposed test has higher power than other tests in most cases. In particular, for the uniform and linear failure rate alternatives, our method has the best performance. A real data example is investigated to show the application of our test.

scholarly journals Efektivitas penyuluhan kesehatan dalam meningkatkan pengetahuan kader posyandu tentang pencegahan pneumonia pada balita

2018 ◽  
Vol 3 (1) ◽  
pp. 22
Author(s):  
Rapitos Sidiq
Keyword(s):  
P Value ◽  
Test Statistic ◽  
Health Seeking ◽  
Significance Level ◽  
Health Counseling ◽  
Work Area ◽  
Before And After ◽  
Seeking Behavior ◽  
Quasi Experimental

Kejadian Pneumonia pada balita masih menjadi permasalahan di dunia termasuk Indonesia. Banyak faktor yang melatarbelakangi kejadian penyakit ini, baik faktor lingkungan maupun perilaku manusia. Salah satu uapaya yang dilakukan untuk pencegahan penyakit ini adalah dengan peningkatan peran kader posyandu untuk kegiatan promotif dan preventif termasuk mempromosikan perilaku pencarian pertolongan kesehatan dan perawatan balita di rumah, sehingga setiap kader dituntut mengetahui tentang pencegahan pneumonia tersebut. Secara umu penelitian ini ingin melihat efektivitas penyuluhan kesehatan dalam meningkatkan pengetahuan kader posyandu tentang pencegahan penyakit pneumonia pada balita di wilayah kerja Puskesmas Darul Kamal Tahun 2017. Penelitian menggunakan metode quasi eksperimental dengan rancangan one group pretest-postest design. Jumlah sampel penelitian 30 orang. Uji statistic yang digunakan paired t-tes tingkat kemaknaan (α) 0,05 (5%). Penelitian ini menghasilkan nilai pengetahuan kader sebelum dan sesudah intervensi adalah 27,17:29,00 dengan p-value 0,003 (< 0,05). Penyuluhan kesehatan efektif dalam meningkatkan pengetahuan kader posyandu tentang pencegahan penyakit pneumoniaKata kunci:   Penyuluhan kesehatan, pengetahuan, kader posyandu, pneumonia, balita  ABSTRACTThe incidence of pneumonia in a toddler is still a problem in the world including Indonesia. Many factors caused the incidence of this disease, both environmental factors, and human behavior. One of the efforts undertaken for the prevention of this disease is by increasing the role of Health Post cadres for promotive and preventive activities including promoting health-seeking behavior and home toddler care so that each cadre is required to know about the prevention of pneumonia. In general, this research would like to see the effectiveness of health counseling in increasing the knowledge of health pos cadres on prevention of pneumonia disease in under-five children in the work area of Puskesmas Darul Kamal 2017. The study used quasi-experimental method with one group pretest-posttest design. The sample size is 30 people. Test statistic used paired t-test significance level (α) 0.05 (5%). This study yields cadre knowledge value before and after intervention is 27,17: 29,00 with p-value 0,003 (<0,05). Health counseling is effective in increasing knowledge of cadres about prevention of pneumonia disease.Keywords: Health counseling, knowledge, cadres, pneumonia, toddler

scholarly journals An approach to gene-based testing accounting for dependence of tests among nearby genes

2021 ◽  
Author(s):  
Ronald J Yurko ◽  
Kathryn Roeder ◽  
Bernie Devlin ◽  
Max G'Sell
Keyword(s):  
Multiple Testing ◽  
Association Studies ◽  
Autism Spectrum ◽  
P Value ◽  
Genome Wide Association Studies ◽  
Strongly Correlated ◽  
Test Statistics ◽  
Test Statistic ◽  
Genome Wide ◽  
Insight Into

In genome-wide association studies (GWAS), it has become commonplace to test millions of SNPs for phenotypic association. Gene-based testing can improve power to detect weak signal by reducing multiple testing and pooling signal strength. While such tests account for linkage disequilibrium (LD) structure of SNP alleles within each gene, current approaches do not capture LD of SNPs falling in different nearby genes, which can induce correlation of gene-based test statistics. We introduce an algorithm to account for this correlation. When a gene's test statistic is independent of others, it is assessed separately; when test statistics for nearby genes are strongly correlated, their SNPs are agglomerated and tested as a locus. To provide insight into SNPs and genes driving association within loci, we develop an interactive visualization tool to explore localized signal. We demonstrate our approach in the context of weakly powered GWAS for autism spectrum disorder, which is contrasted to more highly powered GWAS for schizophrenia and educational attainment. To increase power for these analyses, especially those for autism, we use adaptive p-value thresholding (AdaPT), guided by high-dimensional metadata modeled with gradient boosted trees, highlighting when and how it can be most useful. Notably our workflow is based on summary statistics.

Testing for equality of means with equal and unequal variances

2021 ◽  
Vol 20 (2) ◽  
pp. 51-60
Author(s):  
A.O. Abidoye ◽  
W.A. Lamidi ◽  
M.O. Alabi ◽  
J. Popoola
Keyword(s):  
Agricultural Development ◽  
Secondary Data ◽  
Development Project ◽  
T Test ◽  
Harmonic Mean ◽  
Test Statistics ◽  
Test Statistic ◽  
Unequal Variances ◽  
Equality Of Means ◽  
Pooled Sample

In this paper, we are interested in comparing the conventional t –test with the proposed t – test for testing equality of means with unequal and equal variances. Here, we proposed harmonic mean of variances as an alternative to the pooled sample variance when there is heterogeneity of variances. Two sets of secondary data were obtained from Agricultural Development Project (KWADP) and the Ministry of Agriculture in Ilorin, Kwara State to demonstrate the two test statistics used and the results show that the proposed t – test statistic is found to be appropriate than the conventional t – test statistic when we have unequal variances but the conventional t – test perform better when we have equal variances.

A Bounds Approach to Inference Using the Long Run Multiplier

2019 ◽  
Vol 27 (3) ◽  
pp. 281-301 ◽  
Author(s):  
Clayton Webb ◽  
Suzanna Linn ◽  
Matthew Lebo
Keyword(s):  
Unit Root ◽  
Unit Roots ◽  
Small Sample ◽  
Stochastic Simulations ◽  
Upper And Lower Bounds ◽  
Test Statistics ◽  
Test Statistic ◽  
Independent Variables ◽  
Long Run ◽  
Presidential Success

Pesaran, Shin, and Smith (2001) (PSS) proposed a bounds procedure for testing for the existence of long run cointegrating relationships between a unit root dependent variable ($y_{t}$) and a set of weakly exogenous regressors $\boldsymbol{x}_{t}$ when the analyst does not know whether the independent variables are stationary, unit root, or mutually cointegrated processes. This procedure recognizes the analyst’s uncertainty over the nature of the regressors but not the dependent variable. When the analyst is uncertain whether $y_{t}$ is a stationary or unit root process, the test statistics proposed by PSS are uninformative for inference on the existence of a long run relationship (LRR) between $y_{t}$ and $\boldsymbol{x}_{t}$. We propose the long run multiplier (LRM) test statistic as a means of testing for LRRs without knowing whether the series are stationary or unit roots. Using stochastic simulations, we demonstrate the behavior of the test statistic given uncertainty about the univariate dynamics of both $y_{t}$ and $\boldsymbol{x}_{t}$, illustrate the bounds of the test statistic, and generate small sample and approximate asymptotic critical values for the upper and lower bounds for a range of sample sizes and model specifications. We demonstrate the utility of the bounds framework for testing for LRRs in models of public policy mood and presidential success.

Sign in / Sign up

Export Citation Format

Share Document